1. Field of the Invention
This invention relates to portable, electrically-powered brushing and scrubbing devices and, particularly, to hand-held, battery powered devices of this nature.
2. Description of the Prior Art
It is known in the prior art to provide battery-powered devices having removable attachments for scrubbing, polishing cleaning and the like. Such devices have been disclosed in U.S. Pat. Nos. 4,005,502, 4,027,348, 4,052,766, and 4,158,146.
In general, such prior art devices include a self-contained housing incorporating a power source, such as a battery, a drive motor, a gear and drive shaft assembly, and a switch for activating a drive motor. An output shaft extends outside the housing and is driven by the drive motor through the gear and drive shaft assembly for rotating or oscillating an attachment, such as a brush or pad, secured to the end of the drive shaft.
The prior art devices have presented several drawbacks in their manufacture. For example, in prior art devices the gear and drive shaft assembly includes a double reduction gear set consisting of a simple supported output shaft and gear, a simple supported combination gear and pinion and gear shafts which are separately supported by a gear case, which usually surrounds the entire gear set, and a motor mounting bracket. The motor is generally attached to the motor mounting bracket and the reduction gear set.
Several steps are involved in assembling the drive shaft and gear assembly within the casing of the prior art devices increasing the manufacturing costs. Furthermore, because of the many separate elements involved, extreme accuracy is needed to ensure that the elements are mounted in the proper relationship to ensure bearing alignment and shaft alignment with the motor in the mounting bracket. Where there are various tolerances for the various elements, a tolerance build-up may develop which results in a misalignment.
Another aspect of manufacture which increases cost and the risk of defective products is sealing the housing to prevent liquid contaimination of the electrical and gear components contained within the housing.
The instant invention has overcome many of the disadvantages of prior art devices as it relates to efficient and accurate assembly of the devices and efficient sealing of the housing to prevent liquid contamination. In particular, the instant invention provides a one-piece gear case secured to the drive motor and supporting all of the elements of the gear and drive shaft assembly to ensure uniform alignment. Such a structure leads to a highly efficient, consistent gear set performance. Additionally, the instant invention incorporates a one-piece seal providing effective sealing against liquid contamination as well as an efficient means of assembly of the device.
Additional advantages of the invention are set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.